The system capacity of an existing macro cell network may be increased by deployment of small cells in the underlying macro network. Such deployment may be a co-channel where the macro cells and the small cells operate on the same frequency. Interference from the macro cell is a major issue for co-channel deployment. When the small cell is operating on another frequency layer differently from the frequency layer on which the macro cells are operating, then identification of the inter-frequency small cells when the user equipment is served by the macro cell is a challenging issue. Further, the network including cells with different sizes and overlapping coverage either on same frequency or different frequency is called as Heterogeneous network (HetNet). The small cells include “pico cells”, “femto cells”, relay stations and the like.
In an inter-frequency HetNet deployment, in order to support the handover (offloading) of UE from a macro cell on frequency f1 to the overlaid pico cell on frequency f2, certain enhancements may be required. Existing mobility procedures specified in 3rd Generation Partnership Project (3GPP) version of TS 36.331 may involve configuration of measurement gap to identify and measure the inter-frequency cells. The activation of measurement gap is based on s-measure. For example, a time window of 6 milliseconds is configured as a measurement gap for every 40 to 80 milliseconds by the network to the UE to identify inter-frequency cells. However, a threshold signal strength called as “s-measure” is used as a triggering criterion by the UE for activating the configured measurement gap. In a homogeneous network i.e. network having cells of same size the s-measure rule to trigger inter-frequency scans using the configured measurement gaps work well. This is because all the cells have similar coverage and the inter-frequency cells are not overlaid but the overlap occurs only at cell border. It may be perceived as, this method of looking for inter-frequency cells in the HetNet deployment does not work well because the User Equipment (UE) may have to perform the scan (measurement) for inter-frequency cells all the time and the UE is not governed by the s-measure trigger. Hence, from the perspective of UE the method is power consuming and not very efficient.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.